Fluid reservoir

ABSTRACT

A valve in the flow aperture of a removable coolant reservoir enables coolant to flow between the reservoir and a coolant system while preventing the coolant in the reservoir from spilling when the reservoir is disconnected from the coolant system. A filling tube with a lower end and an air escape passage discourage users from overfilling the reservoir. Once the coolant level reaches the lower end, fluid accumulates in the filling tube, thereby indicating to the user that the reservoir is full. The air escape passage then gradually allows displaced air to escape and coolant in the filling tube to enter the reservoir. An overflow port and tube attached to the filling tube divert excess coolant away from the reservoir. A bleed tube, a bleed port, and a barrier in the reservoir remove bubbles from the coolant system and prevent the removed bubbles from reentering the coolant system.

CROSS-REFERENCE

[0001] This application claims the benefit of priority to U.S.Provisional Patent Application No. 60/286,723 titled “COOLANT RESERVOIRVALVE FOR ENABLING REMOVAL OF RESERVOIR WITHOUT COOLANT LOSS,” filed onApr. 27, 2001, which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a fluid reservoir for a closedloop fluid system such as, for example, is associated with an internalcombustion engine.

BACKGROUND

[0003] Closed loop coolant circulation systems are typically used inconjunction with vehicle engines to dissipate heat that builds up in andaround the vehicle engine. Because the coolant expands and contractsduring normal operation of the coolant circulation system, a coolantreservoir is typically provided to allow excess coolant to flow into thereservoir and allow coolant in the reservoir to flow into thecirculation system when additional coolant is required to fill thecirculation system. Typically, this occurs as the coolants' temperaturefluctuates. Specifically, as the coolant's temperature decreases, ittends to contract. The use of a coolant reservoir allows the coolant toflow therein as the temperature increases, and also allows the fluidtherein to flow back into the system as the temperature decreases.

[0004] In order for the coolant reservoir to facilitate the flow ofcoolant between the coolant circulation system and the reservoir, a flowaperture connecting the reservoir to the coolant system is typicallydisposed at a bottom portion of the reservoir such that the system isgravity fed. Unfortunately, positioning the flow aperture at the bottomof the reservoir makes disconnection and removal of the reservoir fromthe circulation system difficult to accomplish without spilling at leastsome coolant. If the coolant circulation system is used in a vehiclehaving a confined space for the engine components such as a personalwatercraft (PWC), the reservoir must often be disposed in a positionwhere it must be removed in order to access the engine. Whenconventional reservoirs are disconnected from the coolant systems toaccess the engine, the flow aperture becomes exposed to the ambientenvironment and coolant leaks out of the reservoir unless and until theuser somehow seals the flow aperture. To avoid coolant leaks,conventional coolant systems are drained before removing the coolantreservoir. However, draining the entire coolant system prior to removingthe reservoir is both inconvenient and time-consuming.

[0005] The efficiency of coolant circulation systems depends onmaximizing the amount of coolant flowing through the system.Consequently, any bubbles that develop and accumulate in the fluid pathreduce the efficiency of the coolant system. To minimize the presence ofsuch bubbles, conventional coolant systems typically have bleed tubesthat connect the highest point in the coolant system, which is wherebubbles accumulate, to the coolant reservoir in order to encourage thebubbles to flow out of the coolant path and through the bleed tube intothe reservoir. Unfortunately, because the reservoir is itself connectedto the fluid loop, it is possible for the bubbles to merely flow backinto the coolant path through the flow aperture connecting the reservoirto the coolant path. The flow of bubbles back into the coolant pathreduces the efficiency of the system and defeats the purpose of thebleed tube.

[0006] Conventional coolant reservoirs are provided with filling tubesthat allow a user to add more coolant to the coolant system.Unfortunately, users may accidentally overfill the reservoir withcoolant by filling the reservoir above the maximum desired coolant levelor by filling the reservoir above the upper rim of the filling tube.When the reservoir is filled to the maximum desired coolant level, theexpansion of the coolant during operation of the coolant system mayforce even more coolant into the reservoir and cause the coolant tooverflow. As a result, when the reservoir is filled by a user above themaximum level, excess coolant may spill out and harm engine componentsor make a mess.

SUMMARY OF THE INVENTION

[0007] The present invention prevents spills and/or inconveniences fromoccurring when the reservoir is disconnected by providing a vehicle witha fluid system defining a fluid path through which a fluid flows. Thevehicle includes a removable fluid reservoir that has a containerdefining a fluid receiving interior space and having a flow aperture (oropening). The reservoir is removably connected to the fluid path toallow for fluid communication between the interior space of thecontainer and the fluid path via the flow aperture. A valve is mountedto the container at the flow aperture.

[0008] The valve may be a manually operable ball valve. Before removingthe reservoir from the coolant system, a user need only close the valveto avoid leaks. Alternatively, the valve may be a pressure-activatedvalve that is mounted at the flow aperture to enable the fluid to flowfrom the fluid path into the interior space of the container via theflow aperture to compensate for a pressure increase within the fluidpath. The pressure-activated valve substantially prevents the fluid inthe interior space of the container from flowing out through the flowaperture when the container is disconnected from the fluid system.

[0009] The present invention substantially prevents bubbles fromreentering the coolant path once the bubbles have entered the reservoirby providing a vehicle that has a fluid system defining a fluid paththrough which a fluid flows. The first end of a bleed tube has first andsecond ends operatively connected to the fluid path. A fluid reservoirhas a container defining an interior space. A barrier partiallyseparates the interior space into first and second lateral interiorspaces. A bleed port operatively connects an upper portion of the secondinterior space to the second end of the bleed tube such that air bubblesthat have accumulated in the fluid path flow through the bleed tube andport into the second lateral interior space. The barrier is constructedto discourage air bubbles in the second lateral interior space fromentering the first lateral interior space. A fluid passage operativelyconnects lower portions of the first and second lateral interior spacesto permit a substantially bubbleless fluid in the lower portion of thesecond interior space to flow into the first lateral interior space. Apassage between the lower portion of the first interior space and thefluid path permits the fluid in the first interior space to flow intothe fluid path.

[0010] The present invention discourages overfilling and preventsassociated spills by providing a vehicle having a fluid system defininga fluid path through which a fluid is circulated. The vehicle includes afluid reservoir operatively connected to the fluid path. The fluidreservoir comprises a container defining a fluid receiving interiorspace and having a flow aperture that allows for communication betweenthe interior space of the container and the fluid path. The reservoirhas a hollow filling tube having (a) an upper end into which fluid maybe added and (b) a lower end disposed within the interior space at avertical position generally corresponding to a maximum desired fluidlevel. The filling tube enables air that is displaced during fluidfilling to escape from the interior space to an ambient environmentthrough the lower end until a fluid level in the interior space reachesthe lower end. After the fluid level has risen above the lower end,added fluid accumulates in the fluid filling tube. An air escape passagehas first and second ends, the first end of which communicates with theinterior space. Because the passage has a cross-sectional areasubstantially smaller than a cross-sectional area of an inside of thefilling tube, the escape passage enables air to gradually escape fromthe interior space through the escape passage and fluid accumulated inthe filling tube to gradually flow into the interior space when thefluid level is above the lower end.

[0011] The reservoir according to the present invention may furtherinclude an overflow port at an upper portion of the fluid filling tubeto prevent excess coolant from spilling out of the reservoir. Anoverflow tube is removably operatively connected to an external end ofthe overflow port to permit excess vapor and fluid in the fluid fillingtube to flow through the overflow port and tube into a predeterminedlocation such as the bottom of a hull in the case of a personalwatercraft (PWC).

[0012] The second end of the air escape passage may communicate with aportion of the fluid filling tube intermediate the upper and lower endsthereof. Alternatively, the second end of the air escape passage may beoperatively connected to the overflow port and/or tube.

[0013] Other objects, features, and advantages of the present inventionwill become apparent from the following description, the accompanyingdrawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For a better understanding of the present invention as well asother objects and further features thereof, reference is made to thefollowing description which is to be used in conjunction with theaccompanying drawings, where:

[0015]FIGS. 1A, 1B, 1C, and 1D are front, side, back and top plan views,respectively, of a coolant reservoir according to the present invention;

[0016]FIG. 2 is a cross-sectional view of the coolant reservoir of FIG.1D taken along the line 2-2;

[0017]FIG. 3 is a schematic diagram of a coolant circulation systemaccording to the present invention;

[0018]FIG. 4 is a bottom view of a diaphragm valve according to thepresent invention;

[0019]FIG. 5 is a cross-sectional view of an alternative embodiment ofthe present invention; and

[0020]FIG. 6 is a cross-sectional view of an additional alternativeembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0021]FIGS. 1A, 1B, 1C, and 1D illustrate front, side, back and top planviews, respectively, of a coolant reservoir 10 according to the presentinvention. FIG. 2 illustrates a cross-sectional view of the coolantreservoir 10 taken along the line 2-2 of FIG. 1D.

[0022] The coolant reservoir 10 comprises a container that defines acoolant receiving interior space 12. A main coolant port 14 extendsdownwardly from the lower end of the coolant reservoir 10 to form a flowaperture (or opening) 16 that connects to the interior space 12. Acoolant filling port 18 extends upwardly from an upper end of thereservoir 10 and defines a hollow filling; tube 20 that allows a user tofill the reservoir 10 with coolant when necessary. An overflow port 22is disposed at an upper end of the filling tube. A bleed port 24 is alsodisposed at an upper end of the reservoir 10.

[0023]FIG. 3 illustrates a schematic diagram of a coolant circulationsystem 30 according to the present invention. The illustrated coolantcirculation system 30 is a closed loop system that facilitates thecirculation of a coolant. The coolant circulation system 30 can be usedto cool the engine components 32 of various types of vehicles. In theillustrated embodiment, the coolant system 30 is used to cool the enginecomponents 32 of a PWC. However, the coolant system 30 would be equallyapplicable to other types of vehicles such as all-terrain vehicles(ATVs) and snowmobiles, among others. The coolant circulation system 30defines a coolant path 34 that flows through the engine components 32, athermostat 36, and a heat exchanger 38. The engine components 32 mayinclude an exhaust manifold, cylinder heads, or cylinder housing, etc.When coolant in the coolant path 34 flows through the engine components32, the coolant absorbs heat, thereby cooling down the engine components32. The heat absorbed by the coolant is subsequently dissipated in theheat exchanger 38. The volumetric flow of the coolant through the heatexchanger 38 and the engine components may be controlled by a thermostat36 to regulate the temperature of the engine components 32.

[0024] As illustrated in FIG. 3, a connecting tube 40 is operativelyconnected to the coolant path 34 and removably connected to the maincoolant port 14 of the coolant reservoir. When the reservoir isconnected to the coolant circulation system 30, the reservoir 10 isdisposed at a higher elevation than the engine 32. Pressure differencesbetween the coolant path 34 and the reservoir 10 lend to force thecoolant out of the reservoir 10 and into the coolant path 34 via theconnecting tube 40 when the pressure in the reservoir 10 exceeds thepressure in the coolant path 34. Conversely, coolant tends to be forcedout of the coolant path 34 and into the reservoir 10 via the connectingtube 40 when the pressure in the coolant path 34 exceeds the pressure inthe reservoir 10.

[0025] Hereinafter, the main coolant port 14 and pressure-activatedvalve 50 will be described with reference to FIGS. 2, 4, and 6.

[0026] A pressure-activated valve 50 is mounted in the flow aperture 16defined by the main coolant port 14. The pressure-activated valve 50 isdesigned to allow coolant to flow from the interior space 12 of thereservoir 10 out through the main coolant port 14 only when a pressureat an interior end 14 a of the port 14 exceeds a pressure at an exteriorend 14 b of the port 14 by a first predetermined pressure gradient (oramount). To prevent coolant from leaking out through the port 14 whenthe reservoir 10 is disconnected from the coolant system 30, the firstpredetermined pressure gradient is preferably set such that the firstpredetermined pressure gradient is greater than a pressure gradientexperienced when the reservoir 10 is full of coolant and the exteriorend 14 b of the main port 14 is oriented downwardly and exposed to theambient environment, as would be the case when the reservoir 10 is beingdisconnected and removed. At the same time, the first predeterminedpressure gradient is set low enough such that when the reservoir 10 isconnected to the coolant system 30 and the pressure in the coolantsystem 30 is reduced (for example because of lack of coolant), the valve50 will enable coolant in the reservoir 10 to flow through the maincoolant port 14 into the coolant path 34 to maintain an adequate supplyof coolant in the coolant system 30.

[0027] When the main coolant port 14 is operatively connected to thecoolant system 30 via the connecting tube 40, the valve 50 also enablescoolant to flow from the coolant path 34 into the interior space of thereservoir via the main coolant port 14 to compensate for a pressureincrease within the coolant path 34. When pressure builds up in thecoolant system 30, the valve 50 allows excess coolant to flow from thecoolant system 30 into the reservoir 10 via the main coolant port 14.The valve 50 opens when a pressure at the exterior end 14 b of the maincoolant port 14 exceeds the pressure inside the reservoir (i.e., at theinside end 14 a of the port 14) by a second predetermined pressuregradient (or amount). The second predetermined pressure gradient may below or even zero to easily allow coolant to flow from the coolant system30 into the reservoir 10.

[0028] The valve 50 is biased toward allowing coolant to enter thereservoir 10. To accomplish this, the first predetermined pressuregradient is set greater than the second predetermined pressure gradient.

[0029] As illustrated in FIGS. 2, 4 and 6, the pressure-activated valve50 of this embodiment comprises a flexible diaphragm 51. As bestillustrated in FIG. 4, the diaphragm 51 includes first and second slits52, 54 extending at least partially across a middle portion 56 of thediaphragm 51. The first and second slits 52, 54 are preferablyperpendicular to each other. When a sufficient pressure gradient isexperienced across the diaphragm 51, the slits 52, 54 spread apart andallow coolant to flow therethrough. It should be noted that just asingle slit 52 could also be used without departing from the presentinvention, depending upon the pressure gradient desired. As would beappreciated by those skilled in the art, the greater the number of slits52, 54, the easier coolant will flow through the diaphragm 51.

[0030] The middle portion 56 of the diaphragm 51 bulges toward theinterior space 12 of the reservoir 10 when there is no pressure gradientacross the diaphragm 51. This inward bulge ensures that the diaphragm 51is biased toward allowing coolant to flow into the reservoir 10 (thefirst pressure gradient is greater than the second pressure gradient).When coolant pushes outward from inside the reservoir 10 because thepressure therein (at the inside end 14 a of the port 14) is greater thanthe pressure at the outside end 14 b of the main coolant port 14 by lessthan the first pressure gradient, the slits 52, 54 are pushed together,keeping the diaphragm 51 closed. However, when the pressure gradientexceeds the first predetermined pressure gradient (for example when thereservoir 10 is connected to the coolant system 30 and a lack of coolantin the coolant path 34 creates a partial vacuum), the slits 52, 54 bendoutwardly toward the exterior end 14 b of the main coolant port 14 andallow the coolant to flow therethrough into the connecting tube 40 andthe coolant path 34.

[0031] While the illustrated embodiment uses a diaphragm 51 as thepressure-activated valve 50, any other suitable pressure-activated valvethat would be known to one skilled in the art could also be used withoutdeparting from the spirit of the present invention. For example, atwo-way check-valve having predetermined opening pressures could bepositioned in the main coolant port 14. Alternatively, twooppositely-facing one-way check valves could be positioned in parallelrelation to each other in the main coolant port 14.

[0032] When the reservoir 10 is disconnected and removed from thecoolant system 30, the pressure-activated valve 50 substantiallyprevents coolant in the reservoir 10 from leaking out through the maincoolant port 14. This non-leak feature is particularly advantageous invehicles in which the coolant reservoir 10 must be removed in order togain access to components usually associated with the engine. When aconventional reservoir without the valve 50 is used, a user must drainthe coolant system and reservoir before removing the reservoir in orderto prevent coolant from leaking out of the reservoir through the flowaperture onto the vehicle and/or engine as soon as the reservoir isdisconnected. This non-leak feature is well-suited for use in suchclosed-loop coolant systems as are common in snowmobiles, personalwatercraft, and ATVs, where the ability to remove the reservoir withoutdraining the entire coolant system would be most helpful.

[0033]FIG. 5 illustrates an alternative embodiment of the invention.Where elements of this embodiment correspond exactly to elements of theprevious embodiment, identical reference numerals are used. In thisembodiment, a valve 53 is mounted in the main coolant port 55 of thereservoir 57. When a user connects the reservoir 57 to the coolantsystem 30, the valve 53 can be opened to allow coolant to flow betweenthe reservoir 57 and the coolant path 34, as is required during normaloperation of the coolant system 30. Conversely, when the reservoir 57 isoperationally connected to the coolant path 34, the valve 53 can beclosed so that the reservoir 57 can be disconnected without spilling thecoolant or first draining the coolant system 30.

[0034] In the embodiment illustrated in FIG. 5, the valve 53 is amanually-operated ball valve 61. Before disconnecting the reservoir 57from the coolant system 30, the user closes the ball valve 61.Conversely, after connecting the reservoir 57 to the coolant system 30,the user opens the ball valve to allow for coolant communication betweenthe coolant path 34 and the reservoir 57.

[0035] While the illustrated valve 53 is a manually-operated ball valve61, any other type of valve that would be known to one skilled in theart could also be used without departing from the scope of the presentinvention. For example, an automatically-closing quick-disconnect valvecould be used as the valve 53. If a quick-disconnect valve is used,disconnecting the reservoir 57 from the coolant path 34 automaticallycloses the valve. Conversely, connecting the reservoir 57 to the coolantpath 34 automatically opens the valve.

[0036] Hereinafter, the filling tube 20 will be described with referenceto FIGS. 2 and 3.

[0037] The fluid filling port 18 comprises a hollow filling tube 20 thatextends upwardly from an upper end of the reservoir 10. The filling tube20 has an upper end 20 a into which coolant may be added. A cap (notshown) is removably connected to the upper end 20 a to prevent coolantand/or bubbles from spilling out through the upper end 20 a when thecoolant sloshes around in the reservoir 10. A lower end 20 b of thefilling tube 20 is disposed within the interior space 12 at a verticalposition generally corresponding to a maximum desired fluid level. Themaximum desired fluid level is preferably disposed at a predeterminedposition below the top of the interior space 12 so that a pocket ofcompressible gas is maintained within the coolant reservoir 10. Themaximum desired coolant level 59 for this embodiment is marked on thefront of the reservoir 10 as illustrated in FIG. 1A and generallycorresponds to the vertical position of the lower end 20 b. When a userfills the reservoir 10 with coolant through the filling tube 20 and thecoolant level in the reservoir 10 is below the lower end 20 b of thefilling tube 20, displaced air inside the interior space 12 of thereservoir 10 escapes to the ambient environment through the lower end 20b. However, when the coolant level reaches and rises above the lower end20 b of the filling tube 20, displaced air can no longer escape throughthe lower end 20 b. Consequently, additional coolant that is poured intothe upper end 20 a of the filling tube 20 accumulates in the fillingtube 20.

[0038] An air escape passage 60 has a first end 60 a that is operativelyconnected to the interior space 12. A second end 60 b of the air escapepassage 60 is connected to a portion of the filling tube 20 intermediatethe upper and lower ends 20 a, 20 b thereof. Consequently, fluid and aircan flow between the interior space 12 and the intermediate portion ofthe filling tube 20 via the air escape passage 60. The escape passage 60has a cross-sectional area that is substantially smaller than across-sectional area of an inside of the filling tube 20. For example,the diameter of the air escape passage 60 in the illustrated embodimentis approximately 1 mm, as compared to the 22 mm diameter of the fillingtube 20. These dimensions are illustrative only and are not meant to belimiting. As would be understood by one skilled in the art, the precisecross-sectional area of the air escape passage 60 is tuned to match theopening size and shape of the filling tube 20. For example, thecross-sectional shape of the air escape passage 60 and filling tube 20will affect the gas and fluid flow rates therethrough. As described ingreater detail below, the object is to provide an air escape passage 60through which air flows at a substantially slower rate than coolant maybe introduced into the reservoir 10 through the filling tube 20.

[0039] The escape passage 60 enables displaced air to gradually escapefrom the interior space through the escape passage 60 and upper end 20a. As a result, when the coolant level is above the lower end 20 b ofthe filling tube 20, fluid accumulated in the filling tube 20 graduallyflows into the interior space 12 as the displaced air gradually escapesthrough the escape passage 60.

[0040] When a user fills the reservoir 10 with coolant, the user may notbe able to keep careful track of the coolant level in the reservoir 10.The user may therefore fill the reservoir 10 above the maximum desiredcoolant level 59. When this happens, the coolant level rises above thelower end 20 b and stops displaced air from escaping through the lowerend 20 b. As a result, instead of having the coolant level graduallyrise in the wide area of the main interior space 12, the coolant levelquickly rises in the relatively narrow cross-sectional space within thefilling tube 20. The coolant level in the filling tube 20 rapidly risesand indicates to the user that the maximum desired coolant level hasbeen reached. The user thereafter stops filling the reservoir 10, theobserved coolant level in the filling tube 20 having informed the userthat the maximum desired coolant level has been reached. Finally, theair escape passage 60 allows the coolant that accumulated in the fillingtube 20 to flow into the interior space 12 as displaced air escapesthrough the air passage 60 and upper end 20 a. After filling thereservoir, the user replaces the cap.

[0041] Hereinafter, the overflow port 22 and tube 58 will be describedwith reference to FIGS. 2 and 3. The overflow port 22 is operativelyconnected to the filling tube 20 near but slightly below the upper end20 a. The overflow tube 58 is removably operatively connected at one endto the external end of the overflow port 22. The opposite end of theoverflow tube 58 is disposed in an area where spilled coolant will dolittle or no harm. For example, in a PWC, the free end of the overflowtube 58 may be disposed at a bottom of the hull of the PWC (e.g., abilge area) away from the other components of the PWC.

[0042] As noted above with respect to the filling tube 20, the coolantlevel in the filling tube 20 can rise quickly up to the upper end 20 a.As discussed above, the reservoir 10 in a PWC may be disposed above theengine or other vital component(s). In such a case, it is advantageousto prevent excess coolant from spilling out of the reservoir 10 at theupper end 20 a. The overflow port 22 and tube 58 prevent just such aspill. When the coolant level rises in the filling tube 20 to the levelof the overflow port 22 while the user is filling the reservoir and thecap is removed, excess coolant flows through the overflow port 22, whichis disposed below the top rim of the upper end 20 a of the filling tube20, instead of out of the upper end 20 a. The excess coolant flowsthrough the overflow tube 58 and is discharged in a location wheredamage and mess is minimized. In the case of a PWC, the external end ofthe overflow tube 58 is disposed at a bottom of the hull (e.g., in thebilge area).

[0043] The cap (not shown) is preferably a type SAE-J164 cap and servesas a pressure regulator for the reservoir 10. The cap is a spring-loadedpressure cap that normally covers the overflow port 22 and preventscoolant and air from exiting the reservoir 10 via the overflow port.However, when a predetermined pressure develops in the reservoir 10, aspring-loaded portion of the cap lifts slightly and uncovers theoverflow port 22 such that excess pressurized gas and/or coolant (if thecoolant level is sufficiently high) in the reservoir 10 can escape viathe overflow port 22.

[0044] The positioning of the discharge end of the overflow tube 58 atthe bottom of the PWC's hull serves a second function. If a PWC havingthe coolant reservoir 10 flips over, coolant would not spill out becausethe external end of the overflow tube 58 would then be disposed at ahigher elevation (now the bottom of the hull of the PWC) than thecoolant reservoir 10, itself.

[0045] Hereinafter, an alternative embodiment of the present inventionwill be described with reference to FIG. 6. Where the embodimentillustrated in FIG. 6 is identical to the previous embodiment, the samereference numerals are used in order to avoid redundant descriptions ofthe common elements. Like the previous embodiment, an air escape passage63 according to the present embodiment has a first end 63 a operativelyconnected to the interior space 12 of the reservoir 65. Unlike theprevious embodiment, however, a second end 63 b of the air escapepassage 63 is operatively connected to the overflow tube 58 via theoverflow port 67. In the illustrated embodiment, the passage 63 isintegrally formed with the reservoir 65. However, the passage 63 couldalso comprise a separate tube that connects a port in the overflow port67 to a port in the interior space 12. In the present embodiment, apressure-activated valve (not shown) is preferably disposed in theoverflow tube 58 between the second end 63 b and the discharge end ofthe overflow tube 58 so that gas and/or coolant does not escape throughthe escape passage 63 during use of the reservoir 65 unless apredetermined pressure builds up within the reservoir 65. When the capis removed and the reservoir 65 is filled with coolant, however, air canescape from the interior space 12 to the upper end 20 a of the fillingtube via the air escape passage 63 and overflow port 67.

[0046] While in the illustrated embodiments, the second end 60 b, 63 bof the air escape passage 60, 63 connects to either the filling tube 20or the overflow tube 58, the second end of the air escape passage couldalso connect to a variety of other places without departing from thescope of the present invention. For example, the second end of the airescape passage could lead directly to the ambient environment outsidethe reservoir. Regardless of the specific structure employed, the goalof the air escape passage is to allow fluid to be added to the reservoirthrough the filling tube 20 at a substantially faster rate than air canescape from the reservoir through the air escape passage.

[0047] Hereinafter, the bleed port 24 and barrier 62 of the coolantreservoir 10 will be described with reference to FIGS. 2 and 3.

[0048] As can be seen in FIG. 2, a barrier 62 partially separates theinterior space 12 of the reservoir 10 into first and second lateralinterior spaces 12 a, 12 b. The barrier 62 extends upwardly from thebottom of the interior space 12. In the illustrated embodiment, thebarrier 62 includes a lower portion 62 a and an upper portion 62 b thatare separated by a small gap 62 c formed in the barrier 62. The lowerportion 62 a terminates below the filling tube 20 at an elevationslightly above a vertical middle of the interior space 12. The upperportion 62 b extends upwardly from a top of the gap 62 c to the lowerend 20 b of the filling tube 20 and structurally reinforces thereservoir 10. It should be noted that the upper portion 62 b of thebarrier 62 and/or the gap 62 c may be omitted without deviating from thescope of the present invention. Furthermore, the barrier 62 could extendfrom and to various other vertical points within the interior space 12,the purpose being that coolant below the top of the barrier 62 isdiscouraged from quickly flowing back and forth between the first andsecond lateral interior spaces 12 a, 12 b. A coolant passage 64operatively connects lower portions of the first and second lateralinterior spaces 12 a, 12 b to allow coolant to gradually flow back andforth between the lower portions of the first and second interior spaces12 a, 12 b. The main coolant port 14 is disposed in the lower portion ofthe first lateral interior space 12 a. A bleed port 24 is operativelyconnected to an upper end above the second interior space 12 b.

[0049] As illustrated in FIG. 3, a bleed tube 66 is removablyoperatively connected to the bleed port 24 and operatively connected tothe coolant path 34 at a location on the coolant path 34 just before thecoolant leaves the engine 32 to return to the thermostat 36. Thislocation is the highest and hottest position along the coolant path 34and is consequently a natural place for bubbles to develop andaccumulate.

[0050] Hereinafter, the functionality of the barrier 62 will bedescribed. The inventors of the present invention developed the barrier62 and relative positioning of the reservoir 10 components in order tokeep the coolant path 34 as bubble-free as possible. The first end ofthe bleed tube 66 is connected to the coolant path 34 where bubblesaccumulate so that the bubbles accumulating in this area flow throughthe bleed tube 66 and into the second lateral interior space 12 b viathe bleed port 24. Some of the bubbles may condense in the bleed tube 66and splash down into the second lateral interior space 12 b as coolant.The splashing coolant creates additional bubbles in the second lateralinterior space 12 b. Because the bleed port 24 is disposed at an upperend of the second lateral space 12 b, the bubbles tend to stay in theupper portion of the interior space 12. The barrier 62 limits flowbetween the first and second interior spaces 12 a, 12 b in order todiscourage bubbles that enter the second lateral space 12 b through thebleed port 24 from entering the first lateral space 12 a, especiallywhen the coolant level within the reservoir 10 falls below the top ofthe barrier 62. Because bubbles tend to move upward, the fluid passage64, which connects lower portions of the first and second lateralinterior spaces 12 a, 12 b, permits only a substantially bubblelesscoolant in the lower portion of the second interior space 12 b to flowinto the first lateral interior space 12 a. Finally, the main coolantport 14 is disposed at the lower end of the first lateral interior space12 a, which, for the reasons stated herein, is maintained relativelybubble-free. Consequently, bubbles that are formed in the second lateralspace 121) or migrate to the second lateral space 12 b by way of thebleed tube 66 and port 24 tend not to flow back into the coolant path 34through the main coolant port 14.

[0051] While the disclosed embodiment of the present invention is usedin conjunction with a closed-loop coolant system 30, the invention wouldwork equally well with various other fluid systems that are known in theart.

[0052] The foregoing illustrated embodiments are provided to illustratethe structural and functional principles of the present invention andare not intended to be limiting. To the contrary, the principles of thepresent invention are intended to encompass any and all changes,alterations and/or substitutions within the spirit and scope of thefollowing claims.

What is claimed is:
 1. A vehicle comprising: a fluid system defining afluid path through which a fluid flows; and a removable fluid reservoircomprising a container defining a fluid receiving interior space andhaving a flow aperture, said container being removably connected to saidfluid path to allow for fluid communication between said interior spaceof said container and said fluid path via said flow aperture; and avalve mounted to the container at said flow aperture.
 2. The vehicle ofclaim 1, wherein the valve has open and closed positions, and whereinthe valve substantially prevents said fluid in said container fromflowing out through said flow aperture when said valve is closed andsaid container is disconnected from said fluid path.
 3. The vehicle ofclaim 2, wherein said valve is a manually-operated valve.
 4. The vehicleof claim 2, wherein said valve is a ball valve.
 5. The vehicle of claim1, wherein said valve substantially prevents said fluid in said interiorspace of said container from flowing out through said flow aperture whensaid container is disconnected from said fluid path.
 6. The vehicle ofclaim 5, wherein said valve is a pressure-activated valve.
 7. Thevehicle of claim 6, wherein said fluid flows between said interior spaceand said coolant path as a result of pressure differences therebetweenwhen said reservoir is connected to said coolant path.
 8. The vehicle ofclaim 6, wherein said pressure-activated valve allows said fluid to flowfrom said interior space into said fluid path via said flow apertureonly if a pressure within said interior space exceeds a pressure in saidfluid path by a first predetermined amount.
 9. The vehicle of claim 8,wherein said first predetermined amount is greater than a pressureacross said valve when said container is full of fluid and said flowaperture is disconnected from said fluid path.
 10. The vehicle of claim8, wherein said pressure-activated valve allows fluid to flow from saidfluid path into said interior space via said flow aperture only if apressure in said fluid path exceeds said pressure within said interiorspace by a second predetermined amount.
 11. The vehicle of claim 10,wherein said first predetermined amount is greater than said secondpredetermined amount.
 12. The vehicle of claim 1, wherein said vehicleis a personal watercraft.
 13. The vehicle of claim 1, wherein saidvehicle is a snowmobile.
 14. The vehicle of claim 1, wherein saidvehicle is an ATV.
 15. The vehicle of claim 1, wherein said fluid systemcomprises a closed-loop fluid circulation system.
 16. The vehicle ofclaim 15, wherein said fluid circulation system comprises a coolantcirculation system.
 17. The vehicle of claim 1, further comprising anengine, wherein said fluid reservoir is disposed above said engine whenconnected to said fluid system.
 18. The vehicle of claim 6, wherein saidvalve comprises a flexible diaphragm having at least one slit extendingat least partially across a middle portion of said diaphragm.
 19. Thevehicle of claim 6, wherein said at least one slit comprises two slits.20. The vehicle of claim 19, wherein said middle portion of saiddiaphragm bulges toward said interior space when there is no pressuregradient across said valve.
 21. A fluid reservoir for removableconnection to a fluid system in a vehicle, said fluid system defining afluid path through which a fluid flows, said reservoir comprising: acontainer defining a fluid receiving interior space and having a flowaperture, said container being constructed to be removably connected tosaid fluid system of said vehicle to allow for fluid communicationbetween said interior space of said container and said fluid path viasaid flow aperture; and a valve mounted to the container at said flowaperture.
 22. The fluid reservoir of claim 21, wherein said valve hasopen and closed positions, and wherein the valve substantially preventssaid fluid in said container from flowing out through said flow aperturewhen said valve is closed.
 23. The fluid reservoir of claim 22, whereinsaid valve is a manually-operated valve.
 24. The fluid reservoir ofclaim 22, wherein said valve is a ball valve.
 25. The fluid reservoir ofclaim 21, wherein said valve substantially prevents said fluid in saidinterior space of said container from flowing out through said flowaperture when an exterior portion of said valve is exposed to ambientair.
 26. The fluid reservoir of claim 25, wherein said valve is apressure-activated valve.
 27. The fluid reservoir of claim 26, whereinsaid pressure-activated valve allows said fluid to flow from saidinterior space into said fluid path via said flow aperture only if apressure within said interior space exceeds a pressure outside of saidinterior space by a first predetermined amount.
 28. The fluid reservoirof claim 27, wherein said first predetermined amount is greater than apressure across said valve when said container is full of fluid and saidflow aperture is exposed to ambient air.
 29. The fluid reservoir ofclaim 27, wherein said pressure-activated valve allows fluid to flowfrom said fluid path into said interior space via said flow apertureonly if a pressure in said fluid path exceeds said pressure within saidinterior space by a second predetermined amount.
 30. The fluid reservoirof claim 29, wherein said first amount is greater than said secondpredetermined amount.
 31. The fluid reservoir of claim 26, wherein saidvalve comprises a flexible diaphragm having at least one slit extendingat least partially across a middle portion of said diaphragm.
 32. Thefluid reservoir of claim 26, wherein said at least one slit comprisestwo slits.
 33. The fluid reservoir of claim 32, wherein said middleportion of said diaphragm bulges toward said interior space when thereis no pressure gradient across said valve.
 34. A vehicle comprising: afluid system defining a fluid path through which a fluid is circulated;and a fluid reservoir in fluid communication with said fluid path, saidfluid reservoir comprising a container defining a fluid receivinginterior space and having a flow aperture that allows for communicationbetween said interior space of said container and said fluid path; afilling tube having (a) a first end into which fluid may be added and(b) a second end disposed within said interior space at a verticalposition generally corresponding to a maximum desired fluid level; andan air escape passage having first and second ends, said second end ofsaid air escape passage being disposed higher than said second end ofsaid filling tube, said first end of said air escape passagecommunicating with said interior space, said passage having across-sectional area substantially smaller than a cross-sectional areaof an interior of said filling tube, whereby said filling tube enablesair that is displaced during fluid filling to escape from said interiorspace to an ambient environment until a fluid level in said interiorspace reaches said second end, whereupon said second end causes saidfluid to accumulate in said filling tube when said fluid level is abovesaid second end of said filling tube, and whereby said escape passageenables air to gradually escape from said interior space of saidcontainer so that said fluid accumulated in said filling tube graduallyflows into said interior space when said fluid level is above saidsecond end of said filling tube.
 35. The vehicle of claim 34, whereinsaid second end of said air escape passage communicates with a portionof said filling tube intermediate said first and second ends thereof.36. The vehicle of claim 34, wherein said vehicle comprises an enginefor propelling said vehicle and said fluid reservoir is disposed abovesaid engine.
 37. The vehicle of claim 34, wherein said reservoir furthercomprises an overflow port at an upper portion of said filling tube. 38.The vehicle of claim 37, wherein said fluid system further comprises anoverflow tube removably fluidly communicating with an external end ofsaid overflow port to permit excess fluid in said filling tube to flowthrough said overflow port and tube to a predetermined location.
 39. Thevehicle of claim 38, wherein said second end of said air escape passagecommunicates with said overflow tube.
 40. The vehicle of claim 37,wherein said second end of said air escape passage fluidly communicateswith said overflow port.
 41. The vehicle of claim 38, wherein saidvehicle is a personal watercraft and said predetermined location is abottom of a hull of said personal watercraft.
 42. The vehicle of claim34, wherein said fluid system comprises a closed-loop fluid circulationsystem.
 43. The vehicle of claim 34, wherein said fluid system is acoolant circulation system.
 44. The vehicle of claim 34, wherein thevehicle is an ATV.
 45. The vehicle of claim 34, wherein the vehicle is asnowmobile.
 46. A fluid reservoir for removable fluid communication witha fluid system in a vehicle, said fluid system defining a fluid paththrough which a fluid flows, said fluid reservoir comprising: acontainer defining a fluid receiving interior space and having a flowaperture constructed to be removably connected to said fluid path toallow for fluid communication between said interior space of saidcontainer and said fluid path via said flow aperture; a filling tubehaving (a) a first end into which fluid may be added and (b) a secondend disposed within said interior space at a vertical position generallycorresponding to a maximum desired fluid level; and an air escapepassage having first and second ends, said first end of said air escapepassage communicating with said interior space, said passage having across-sectional area substantially smaller than a cross-sectional areaof an inside of said filling tube, whereby said filling tube enables airthat is displaced during fluid filling to escape from said interiorspace to an ambient environment through said second end of said fillingtube until a fluid level in said interior space reaches said second endof said filling tube, whereupon said second end of said filling tubecauses said fluid to accumulate in said filling tube when said fluidlevel is above said second end of said filling tube, and whereby saidescape passage enables air to gradually escape from said interior spaceso that said fluid accumulated in said filling tube gradually flows intosaid interior space when said fluid level is above said second end ofsaid filling tube.
 47. The reservoir of claim 46, wherein said secondend of said air escape passage communicates with a portion of saidfilling tube intermediate said first and second ends thereof.
 48. Thereservoir of claim 46, wherein said reservoir further comprises anoverflow port disposed at an upper portion of said filling tube suchthat when a fluid height in said filling tube reaches said overflowport, said fluid flows out of said filling tube through said overflowport.
 49. The reservoir of claim 48, wherein said second end of said airescape passage is in fluid communication with said overflow port.